Effects of R-ratio and wave form on the fatigue of 63Sn-37Pb solder used in electronic packaging

The present investigation is a continuation of the authors' studies into the fatigue of Pb-Sn solder joints related to electronic packaging. Total-strain-controlled, low-cycle fatigue tests in shear at 300 K were conducted on 63Sn-37Pb solder joints with ramp straining (R=0 and R=-1) and square-wave straining (R=-1). All results followed the Coffin-Manson equation. Both R and waveform had an effect on changes in the hysteresis loops as a function of the number of cycles.<>